The present invention relates to the general field of aviation turbine engines, and more particularly it relates to a fitted platform for a turbine engine fan.
The fan of an aviation turbine engine generally comprises a plurality of movable blades with platforms being present between them at their roots. The main function of the platform is to define the flow passage for the gas stream entering into the turbine engine. Because of their aerodynamic function, the flow passage walls of platforms need to be in intimate contact with the adjacent blades in order to provide sealing between the platforms and the blades. In the event of ingesting objects (blocks of ice, birds, etc.), fan blades may be impacted and become deformed. The deformation is then transmitted to the flow passage walls of the platforms which must, wherever possible, avoid becoming damaged or broken, even in the event of a major impact.
In order to avoid damaging blades and platforms, the blades and the top walls of platforms need to make contact appropriately. For this purpose, it is known to thin down the margins of a platform top wall where they are to come into contact with blades, i.e. to reduce wall thickness locally in the contact zones between a blade and a platform. These thin margins enable contact between the platforms and the blades to be made more flexibly, and they can be effective in damping impacts and thus reduce the damage that results therefrom on the blades and the platforms.
When the platforms are made of composite material made of fiber reinforcement densified by a matrix, thinning down the margins of the flow passage wall generally requires a machining step. In particular, with thin margins, it is often necessary to put gaskets into place in order to provide sealing between the blades and the platform. The machining step is difficult to perform and it lengthens methods of fabricating and installing platforms, thereby increasing costs.
There therefore exists a need for a fitted platform for a fan blade that is easy and inexpensive to fabricate and that does not present the above-mentioned drawbacks.